#include <stdio.h>

/*if else 语句*/
/*
int main()
{
    int input = 0;

    printf("hello world!\n");
    printf("choose?\n");

    scanf("%d",&input);

    if (input == 1)
    {
        printf("great\n");
    }
    else 
    {
        printf("try again\n");
    }

    return 0;
}
*/

/*while循环*/

int main()
{
    int line = 0;

    while(line < 20)
    {
        printf("try again,%d\n",line);
        line++;
    }

    if(line >= 20)
    {
        printf("great!");
    }
    else
    {
        printf("do again");
    }

    return 0;
}
